Encyclopedia of Database Systems

2018 Edition
| Editors: Ling Liu, M. Tamer Özsu

Logical and Physical Data Independence

  • Ramez Elmasri
Reference work entry
DOI: https://doi.org/10.1007/978-1-4614-8265-9_80651

Synonyms

Database schema; DBMS

Definition

These concepts were developed to separate the database schema that the users and programmers see from the storage details and indexing methods of the database and are best explained using the database architecture known as the three-schema architecture. This architecture assumes that there are database schemas or descriptions at three levels: (1) the user view level, which describes a portion of the database for a particular class of users; (2) the conceptual schema, which describes a whole database in a representational data model such as the relational model or the object model; and (3) the internal schema, which describes the storage structures and indexing methods that describe the database files. Physical data independence is defined as the capability to change the internal schema (storage structures/indexes) without having to change the conceptual schema. Logical database independence is defined as the capability to change the conceptual...

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Recommended Reading

  1. 1.
    Elmasri R, Navathe S. Fundamentals of database systems. 7th ed. Pearson; 2016.Google Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Computer ScienceThe University of Texas at ArlingtonArlingtonUSA

Section editors and affiliations

  • Ramez Elmasri
    • 1
  1. 1.Computer ScienceThe University of Texas at ArlingtonArlingtonUSA